In a network field, the ITU-T recommends the Optical Transport Network (OTN) where packet-based data may be integrally handled as a technique of a next-generation transportation having applications expected to be expanded.
In the OTN, it is possible to integrally handle TDM-based data and packet-based data, the TDM-based data being used in, for example, Synchronous Optical Network/Synchronous Digital Hierarchy (SONET/SDH), and the packet-based data being used in, for example, Ethernet (registered trademark, hereinafter simply referred to as a “LAN”).
In a specification of the OTN, an Optical Channel Data Unit flex (ODUflex) is described which provides a variable bandwidth in accordance with a demand to increase the efficiency of the transmission of the packet-based data which are the current main traffic.
In the ODUflex, it is possible to flexibly increase the bandwidth. However, in an OTN where multi-stage cross-connections are arranged, a byte array may change during demapping.
To overcome such a problem, there is a proposed technique where when two ODU0s are used in a transmission path and one of the two ODU0s is then removed, the ODU path is replaced (reconfigured) while control is performed that outputs a signal to a remaining ODU path, the signal being the same as that to be output to the removed ODU path.
For related art, reference may be made to Japanese Laid-open Patent Publication No. 2011-176619.